Abstract: A method for determining the diffusion radius of in-situ injection and remediation of contaminated soil and groundwater. According to the triangle method, the hole spacing is perpendicular to the groundwater flow direction, the row spacing is along the groundwater flow direction, and the flow diffusion in the groundwater during the effective time of the remediation agent reaction is considered. Under high pressure rotary injection, the remediation agent and a certain proportion of bromide ions are simultaneously injected into the aquifer as a tracer. The diffusion of the agent is determined by observing the phenomenon of slurry-returning and slurry-channeling of adjacent injection points. After the completion of the injection, the groundwater is quickly sampled in fixed depth, the tracer concentration is quickly detected on site, and the concentration of bromide ions in the groundwater is compared with the background value. Comprehensive determination determines the optimal diffusion radius.

Abstract: An in-situ injection of soil and groundwater—high pressure rotary jet grouting in-situ remediation system and method. The system has an agent dispensing station, high pressure grouting pump, air compressor, rotary jet grouting drilling machine, second double-pipe water flow joint, automatic lifting mechanism for grouting drill pipe of rotary jet grouting drilling machine, high pressure jet drill pipe, inner tube for high pressure jet triple drill pipe, outer tube for high pressure jet triple drill pipe, agent jet nozzle, an air jet nozzle, cemented carbide block and a drill bit. Parameters are arranged according to the triangle method to ensure that the remediation area is covered within the diffusion radius of the agent. After positioning the GPS measuring point, a guided-boring rig is positioned at the center of the injection point.

Abstract: An in-situ chemical oxidation high pressure injection optimization remediation method for soil and groundwater. A field test determines the diffusion radius of the injection agent in a typical formation, the maximum single-hole grouting amount per linear meter and the injectability parameter. Density-increased supplementary investigation, soil and groundwater data analysis, is divided by spatial distribution into four concentration main partitions, eight concentration sub-partitions. By optimizing the single-hole grouting amount per linear meter, the preparation concentration of the oxidant, and the parameters of the formulation of each partition, the optimization of the dosing ratio of remediation agent of each partition is achieved. The specific construction performance is to adjust the lifting speed of the high pressure injection drill pipe during the injection process for finally achieve the purpose of reducing the dosing ratio parameters of the agent in the remediation plot.